Despite these early accolades, Smith has yet to really step out of the shadows. His debut album, In The Lonely Hour, won't even be released until May 2014. Instead, his stock has risen as a result of adding soulful guest vocals for two recent hits he co-wrote: Disclosure's Latch and Naughty Boy's chart-topping La La La.

In this sense he's part of a group of solo artists who are launching careers off the back of being featured artists on other people's records, from Ella Eyre to Sampha (whose vocals convey a similar sense of crushed pain as Smith's do).

Nick Raphael, the president of Capitol Records who signed Smith in 2012, says he never planned to launch his career through these featured appearances. Instead, when Raphael first heard Smith's track Lay Me Down in September 2012, he was so blown away by his vocal talent and "endearing personality" his only plan was to invest time and energy launching the singer as a solo star in his own right. Label partner Jo Charrington was similarly convinced, telling Raphael to cancel a planned New York trip and not to come into the office until Smith had been signed.

As they thrashed out a deal, Smith's collaboration with Disclosure took off. Latch became a Top 20 hit, providing an unexpected but very welcome springboard for Smith's career. "It's always a dream to have something like that for your artist," says Raphael. "But much as we like to pride ourselves in having a plan, we didn't imagine it would happen like this."

Because time was spent making sure Smith's solo album was as good as it could be, Capitol also agreed to let Naughty Boy release his collaboration with Smith, La La La, in May 2013. It became the first No 1 for both artists, selling more than 3m copies worldwide.

Deliberate or not, these featured vocalist slots have raised Smith's profile immeasurably without exposing him too soon to the harsh glare of the music industry spotlight. Despite his obvious vocal talent, Smith's challenge now will be establishing himself as a solo artist with a sellable personality to match the voice. His ballad-focused solo output has to date stuck close to the middle of the road, although that never harmed Adele or Sandé. Promisingly, the singer seems keen to stamp his own outlook on to his music too. "I'm kind of sick of listening to albums about the turmoils of relationships, never having had one," he told the Observer last year. "I wanted to write an album for people who have never been in love. I want to be a voice for lonely people."

Smith certainly has the background to succeed: the singer has been performing since the age of six and seems to have been groomed for pop stardom. In 2009, a story emerged that his mother, a highly paid City trader, was suing her employers for unfair dismissal: she claimed that her bosses were unhappy that she was spending too much time promoting her son's fledgling pop career.

Smith's also not short on celebrity connections. His BBC Sound Of poll victory was announced on Twitter not by the corporation themselvesitself but by a tweet from Lily Allen who was clearly privy to insider information. It emerged that Smith is actually the singer's third cousin, although he claims never to have met her. Along with everything else in Sam Smith's life, that looks set to change in 2014 when he sets out to really make a name for himself.